DAYUAN Petrol Engine Compression Tester Kit — 3" Dual-Scale Gauge, Blue Case, Multi-Adapter Set

DAYUAN Professional Petrol Engine Compression Tester Kit is a complete, portable set for measuring cylinder compression on petrol engines with a 3-inch dual-scale gauge and multiple adapters.

This kit gives technicians and home mechanics the tools to check engine health by measuring compression pressure in gasoline engines. Housed in a durable blue case, the set includes a 3" gauge with dual psi/bar scales, threaded fittings for common spark plug sizes, and two rubber cone ends to perform quick, non-threaded checks. It's designed to handle a wide range of vehicles and spark plug depths so you can diagnose ring, valve, or head sealing issues efficiently.

How do I use the DAYUAN compression tester on a petrol engine?

Using the tester involves removing the spark plug, selecting the correct adapter, and cranking the engine while watching the gauge needle stabilize. Always follow basic safety (engine off for fitting, ignition disabled before cranking) and consult your vehicle manual for cylinder-specific procedures.

• Remove spark plug and attach appropriate adapter (14mm/18mm or listed fittings).
• Install tester into the spark plug hole or use a rubber cone for quick checks.
• Disable ignition, crank the engine several revolutions, and read stabilized pressure on the 0–300 psi / 0–20 bar gauge.
• Compare readings across cylinders to spot leaks, worn rings, or valve issues.

Which vehicles and spark plug types are supported by the kit?

The set covers many common petrol engine spark plug threads and depths via included fittings and adapters. It is adaptable to various passenger cars, light trucks, motorcycles, and small engines where the listed thread sizes match.

• Fittings: M10, M12, M14, M18 (male, with O-ring) to suit different plug threads.
• Includes 14mm and 18mm spark plug adapters for common applications.
• Two rubber cone ends allow quick, non-threaded checks on uneven or recessed sockets.
• Works with most petrol engines that accept the included thread sizes and adapters.

What does the 3" dual-scale gauge tell me and why it matters?

The 3-inch gauge shows both psi (0–300) and bar (0–20) so you can read pressure in the unit you prefer or match manufacturer specs. A clear dual-color scale helps you quickly compare values and detect low-compression cylinders that warrant further investigation.

• Large 3" dial for easy reading under workshop lighting.
• Dual scales: 0–300 psi and 0–20 bar to match different spec formats.
• Needle stability after cranking indicates true cylinder pressure.
• Use comparative readings across cylinders to identify anomalies.

What accessories are included and how do they improve testing?

The kit contains a selection of threaded fittings, spark plug adapters, rubber cones, and a flexible hose to reach awkward plug locations. These components expand compatibility and speed up testing without improvising adapters.

• Threaded fittings: M10, M12, M14, M18 with O-rings for secure seals.
• Spark plug adapters: 14mm and 18mm for common plug sizes.
• Two rubber cone ends for rapid checks when threading isn’t practical.
• Sturdy blue storage case keeps components organized and protected.

Who is this for: The DAYUAN compression tester kit is aimed at professional mechanics, automotive technicians, and DIY enthusiasts who perform routine engine diagnostics on petrol engines. It suits anyone who needs a reliable, portable tool to measure cylinder compression across a broad range of vehicles and spark plug configurations without resorting to custom fittings.